The public/private partnership will deliver a range of services, including HR, and involves more than 1,000 public sector employees transferring to the new venture. Local officials from trade union Unison claimed the deal was never fully debated and expressed concerns that partnerships with private companies raised major conflicts within the culture of local government.

The union has now filed a tribunal claim against the council, citing a failure to consult regarding the staffing agreement element of the project. But Richard Crouch, head of HR at Somerset County Council, said he was “surprised” by the move.

“The council has had no complaints from any member of staff either before or after the deal was signed,” he told Personnel Today. “Unison was involved throughout the process so I’m not sure of the reasoning behind the complaint.”

All public sector staff working for Southwest One have been seconded to the company on their existing terms and conditions, Crouch added. Their employment has also been guaranteed for the duration of the 10-year contract.

Despite this, Unison has called for a full inspection of the deal, accusing the decision making of lacking public accountability and insisting jobs remained under threat. Crouch admitted the deal was “shrouded in secrecy” but maintained this was because of commercial confidentiality.

A spokesman for the Audit Commission spending watchdog said an official report into the project would be published in the coming weeks. Southwest One was unavailable for comment.